Strip coilers have been made with a coiling and uncoiling expandable drum having an outward flange on one end releasably connected to a mating outward flange on the end of a rotative drive shaft, by a collar or clamping ring having inward flanges embracing the outward flanges of the drum and shaft. The drum flange and the corresponding flange of the collar form a bayonet joint so that by relative rotation of the collar and drum, the drum and its flange can be released. To force the drum and shaft flanges together to provide a firm connection, one of the collar's inward flanges and one of the outward flanges of the shaft or drum have been provided with rotatively actuated cam surfaces so that by forcible rotation, the two outward flanges are mechanically forced together.
A strip coiler operates under conditions of high stress. Therefore, for the partial rotation required to release the drum, an undesirable torque force is required, customarily obtained by the use of a spanner wrench having a very long handle, the use of a heavy hammer often being required as an assisting force. For reinstallation of the drum and its flange, the same kind of expedients are required.
Plainly, an undesirable amount of trouble is involved in releasing and reinstalling the drum of such a coiler. In addition, the cam surfaces required involve relatively precision machining operations to ensure a proper cam action, this representing an undesirable coiler manufacturing expense.
The object of the present invention is to provide a coiler permitting relatively easy release of the coiler and drive shaft flanges and which eliminates the cam surfaces and their attendant manufacturing expense.